THU0523 CLINICAL UTILITY OF TESTING CONVENTIONAL AND NON-CONVENTIONAL ANTI-PHOSPHOLIPID ANTIBODIES IN SUSPECTED OBSTETRIC ANTI-PHOSPHOLIPID SYNDROME

Background:

Anti-phospholipid syndrome (APS) is an important cause for recurrent pregnancy losses (RPL). Conventional APS antibodies (aPLs) like lupus anti-coagulant (LA), anti-cardiolipin(ACL) and anti-beta 2 glycoprotein I (anti-β2 GP I) are not present in significant number of obstetric APS(OAPS) patients, leading to a state described as “ sero-negative” OAPS (SNOAPS). Recent literature shows non-conventional aPLs like Anti phosphatidylserine-prothrombin complex (Anti-PSPT) and Anti-Annexin V (Anti-Ann V) can be positive in up to 50% of SNOAPS patients

Objectives:

Testing the performance of conventional and non-conventional aPLs in suspected OAPS patients (obstetric events as defined in the Sydney classification criteria for APS)

Methods:

We performed a retrospective chart review of 101 patients who underwent combined testing for non-conventional aPLs for suspected OAPS from May 2016 to November 2019 at our department. Patients were categorized into OAPS cases (n=50, median age 31 years) and controls (n=51, median age 30 years) based on their fulfillment of clinical definition of OAPS events defined by Sydney criteria. Conventional aPLs were tested by methods adapted in Sydney criteria and Anti PSPT /Anti Ann V were tested by commercial ELISA. The sample size(n=101) has 95% confidence interval with a margin of error of 10% for the objective of the study.

Results:

36 cases (72%) were ‘sero-positive’ & 14 cases (28%) were truly ‘sero-negative’ for conventional aPLs. 5 (35.7%) of the SNOAPS patients were positive for Ant-PSPT and/or Anti AnnV antibodies. Performance of the various aPLs in suspected OAPS is displayed in Table 1 & Figure 1.

Table 1

showing the performance of the various conventional and non-conventional APLs in suspected obstetric APS cases

AntibodySensitivitySpecificityLikelihood Ratio(+)Likelihood Ratio (-)Positive Predictive ValueNegative Predictive ValueAccuracyYouden’s IndexLA50%94.1 %8.50.589.3%65.7%72.3%44.1%ACL32%98%16.30.794.1%59.5 %65.3%30 %anti β2 GP I IgM38.4%91.4 %4.50.783.3%57.1 %63.5%29.8%anti β2 GP I IgG24%96.1 %6.10.885.7%56.3%60.4%20.1%Anti PSPT28%96.1 %7.10.787.5%57.6 %62.4%24.1%Anti AnnV28%98 %14.30.793.3%58.1%63.4%26%Conventional APLs72%88.2%6.10.385.7%76.3 %79.8%60.2%Non-conventional APLS38%94.1%6.40.786.4%60.7 %66.3%32.1%All APLs82%86.3%6.000.2085.4%83 %84.2%68.3%Figure 1

showing the comparative diagnostic performance of Conventional aPL testing vs Combined testing along with non-conventional aPLs in suspected obstetric APS scenario

Conclusion:

In a delicate situation like RPL, performance of non-conventional aPLs on their own, though not as sensitive as conventional aPLs, still demonstrate better specificity. Non-conventional APLs can newly identify 1/3rd of SNOAPS as APS. The real value of testing Anti PSPT & Anti Ann V in RPL, is combined testing with conventional aPLs wherein they improve the sensitivity and accuracy of diagnosis of OAPS by 10% & 4.4 % respectively, with only 1.9% drop in specificity. Non-conventional aPLs should be tested in SNOAPS.

Disclosure of Interests:

None declared

Type-3 von Willebrand disease in India-Clinical spectrum and molecular profile

INTRODUCTION

Type 3 von Willebrand disease (VWD) is the rare and most severe form of VWD which results from a near-complete deficiency of the von Willebrand factor (VWF). This study evaluates in detail the molecular pathology of type-3 VWD in India. One hundred and two patients from 90 families were evaluated.

PATIENTS AND METHODS

Phenotypic data, including bleeding scores (BS), were documented using structured questionnaires. Diagnosis of type 3 VWD was based on undetectable VWF antigen levels in the plasma. Genomic DNA from these patients was screened for mutations in VWF gene. Structural modeling and expression studies were carried out for missense mutations.

RESULTS

Out of 102 patients, mutations could be identified in 91% (n = 93). Fifty-five different gene variants were identified. Thirty-four (61.8%) were novel. Mutations could be identified in both the alleles in 90 patients, while no causative mutation could be identified in 9 patients; twenty-four (23.5%) patients had mutations clustered in the propeptide region of VWF. Interestingly, five mutations accounted for the defects in 37/93 (39.8%) patients. Structural analysis and in vitro studies on missense mutations imply impaired processes associated with secretion of VWF.

CONCLUSION

This study is one of the largest series to define the molecular basis of type-3 VWD.

Vascular Anomalies of the Head and Neck Region

Vascular anomalies of the head and neck region are a complex group of lesions that challenge the head and neck physicians. From the very understanding of the difference between its two distinct forms, hemangiomas and vascular malformations to its management remain confusing. The review of this anomaly attempts at comprehensively understanding the disease. Vascular anomalies are easily diagnosed by their clinical presentation, but choice of imaging and management for this spectrum of lesions is varied. The author attempts to categorize the required imaging for the lesion with suggestions on the management of both hemangiomas and vascular malformations. The available treatment options are discussed, and a comprehensive algorithm for management is suggested. Further research in developing drugs that could restrict the growth of these lesions would be the future of the management of vascular lesions.

Diagnostic laboratory for bleeding disorders ensures efficient management of haemorrhagic disorders

Haemorrhagic disorders like Postpartum haemorrhage and Dengue haemorrhagic fever are life threatening and requires an active and efficient transfusion service that could provide the most appropriate blood product which could be effective in managing them. This would essentially require prompt identification of the coagulopathy so that the best available product can be given to the bleeding patient to correct the identified haemostatic defect which will help control the bleeding. This would only be possible if the transfusion service has a laboratory to correctly detect the haemostatic defect and that too with an accuracy and precision which is ensured by a good laboratory quality assurance practices. These same processes are necessary for the transfusion services to ensure the quality of the blood products manufactured by them and that it contains adequate amounts of haemostasis factors which will be good to be effective in the management of haemorrhagic disorders. These issues are discussed in detail individually in the management of postpartum haemorrhage and Dengue haemorrhagic fever including when these can help in the use of rFVIIa in Dengue haemorrhagic fever. The requirements to ensure good-quality blood products are made available for the management of these disorders and the same have also been described.

Hemostatic Abnormalities in Severe Renal Failure: Do They Bark or Bite?

Abnormal primary hemostasis is believed to be the most significant contributor to uremic bleeding. This study aimed to describe the prevalence and profile of primary and secondary hemostatic disorders in patients with chronic kidney disease (CKD) Stages 4 and 5 and to determine their association if any, with degree of uremia. Stages 4 and 5 predialysis CKD patients attending nephrology outpatient clinic were prospectively recruited and the following bleeding parameters were measured in all patients: platelet count, bleeding time (BT), Factor VIII assay, von Willebrand factor antigen (vWF:Ag), vWF:ristocetin cofactor activity (vWF:RCo), ratio of vWF:ristocetin cofactor activity to vWF antigen (vWF:RCo/vWF:Ag), prothrombin time (PT), and activated partial thromboplastin time (aPTT). Forty-five patients (80%, males) with a mean age of 39.4 years, 82% (n = 37) in Stage 5 CKD, were recruited for the study. The prevalence of thrombocytopenia was significantly higher among patients from West Bengal (15/26, 57.7%) compared to other study patients (2/19, 10.5%; P = 0.001); however, all had macrothrombocytes with normal BT, suggestive of the Harris syndrome. Factor VIII, vWF:Ag, vWF:RCo, vWF:RCo/vWF:Ag ratio, BT, PT, and aPTT were abnormal in 0 (0%), 0 (0%), 0 (0%), 4 (8.8%), 1 (2.2%), 7 (15.6%), and 5 (11.1%) patients, respectively. Except for thrombocytopenia, the prevalence of hemostatic abnormalities did not differ between CKD Stages 4 and 5. Hemostatic abnormalities are uncommon in Stages 4–5 CKD and except for thrombocytopenia, are not associated with degree of uremia. Constitutional macrothrombocytopenia is associated with normal BT even in CKD.

Utility of neutrophil volume conductivity scatter (VCS) parameter changes as sepsis screen in neonates

OBJECTIVE

The objective of this study was to determine changes in neutrophil volume conductivity scatter (VCS) parameters and their distribution widths (DW) in neonatal sepsis and to estimate their optimal cutoff levels using receiver operating characteristic (ROC) curves.

STUDY DESIGN

In a cohort of neonates evaluated for sepsis, blood counts and blood culture were performed initially, with repeat counts and C-reactive protein (CRP) done after 24 to 48 h. Neutrophil VCS parameters from both the initial and repeat blood counts were analyzed. Babies were classified as having blood culture-positive sepsis, probable sepsis (clinical course consistent with sepsis and CRP-positive, but culture-negative) and no sepsis (clinical course not compatible with sepsis, culture- and CRP-negative).

RESULTS

A total of 600 babies were included: 240 (40%) babies in the sepsis group and 360 (60%) babies in the control group. All the neutrophil VCS parameters and their DWs (except for low angle light scatter in the repeat counts) were significantly different between the two groups, with an area under curve in the ROC curve of >0.6 for most parameters. The five most significant VCS parameters (mean neutrophil volume (MNV), median angle light scatter (MALS), lower median angle light scatter (LMALS), MNV-DW and ALL-DW) had around 65 to 75% sensitivity and specificity. A combination of leukopenia, thrombocytopenia, MNV and LMALS had a likelihood ratio (LR)+ of 15.3 and LR- of 0.17. With a pre-test probability of 40%, post-test probability increased to 91% for a positive test and decreased to 10% for a negative test. A prospective validation study was performed recruiting an additional 60 babies, which showed similar results, assuring that the cutoffs were robust.

CONCLUSION

Neutrophil VCS parameters cannot be considered as stand-alone tests to diagnose or rule out neonatal sepsis, but can be used in combination with other hematological screening tests to improve the diagnostic accuracy of the neonatal sepsis screen.

A Personalized Approach to Biological Therapy Using Prediction of Clinical Response Based on MRP8/14 Serum Complex Levels in Rheumatoid Arthritis Patients

Objectives

Measurement of MRP8/14 serum levels has shown potential in predicting clinical response to different biological agents in rheumatoid arthritis (RA). We aimed to develop a treatment algorithm based on a prediction score using MRP8/14 measurements and clinical parameters predictive for response to different biological agents.

Methods

Baseline serum levels of MRP8/14 were measured in 170 patients starting treatment with infliximab, adalimumab or rituximab. We used logistic regression analysis to develop a predictive score for clinical response at 16 weeks. MRP8/14 levels along with clinical variables at baseline were investigated. We also investigated how the predictive effect of MRP8/14 was modified by drug type. A treatment algorithm was developed based on categorizing the expected response per drug type as high, intermediate or low for each patient and optimal treatment was defined. Finally, we present the utility of using this treatment algorithm in clinical practice.

Results

The probability of response increased with higher baseline MRP8/14 complex levels (OR = 1.39), differentially between the TNF-blockers and rituximab (OR of interaction term = 0.78), and also increased with higher DAS28 at baseline (OR = 1.28). Rheumatoid factor positivity, functional disability (a higher HAQ), and previous use of a TNF-inhibitor decreased the probability of response. Based on the treatment algorithm 80 patients would have been recommended for anti-TNF treatment, 8 for rituximab, 13 for another biological treatment (other than TNFi or rituximab) and for 69 no recommendation was made. The predicted response rates matched the observed response in the cohort well. On group level the predicted response based on the algorithm resulted in a modest 10% higher response rate in our cohort with much higher differences in response probability in individual patients treated contrary to treatment recommendation.

Conclusions

Prediction of response using MRP8/14 levels along with clinical predictors has potential in personalizing treatment for RA patients starting biological anti-rheumatic treatment, and might increase cost-effectiveness.

Economic evaluation of a tight-control treatment strategy using an imaging device (handscan) for monitoring joint inflammation in early rheumatoid arthritis

OBJECTIVES

To evaluate the cost-effectiveness of a tight-control treatment strategy using the handscan (TCHS) compared to using only clinical assessments (TC) and compared to a general non-tight-control treatment strategy (usual care; UC) in early rheumatoid arthritis (RA).

METHODS

Data from 299 early RA patients from the CAMERA trial were used. Clinical outcomes were extrapolated to Quality Adjusted Life Years (QALYs) and costs using a Markov model. Costs and QALYs were compared between the TC and UC treatment strategy arm of the CAMERA trial and a simulated tight-control treatment strategy using the handscan (TCHS). Incremental Cost-Effectiveness Ratios (ICERs) were calculated and several scenario analyses performed. All analyses were performed probabilistically to obtain confidence intervals and costs-effectiveness planes and acceptability curves.

RESULTS

In TCHS, €4,660 (95% CI -€11,516 to €2,045) was saved and 0.06 (95% CI 0.01 to 0.11) QALYs were gained when compared to UC, with an ICER of €77,670 saved per QALY gained. Ninety-one percent (91%) of simulations resulted in less costs and more QALYs. TCHS resulted in comparable costs or even limited savings €642 (95% CI -€6,903 to €5,601)) and comparable QALYs to TC. In all scenario analyses, TCHS and TC were found to be cost effective as compared to UC.

CONCLUSIONS

A tight-control treatment strategy is highly cost-effective compared to a non-tight-control approach in early RA. Using the handscan as a monitoring device might facilitate implementation of tight-control treatment strategy at comparable costs and with comparable effects. This approach should be investigated further.

Systemic biochemical markers of joint metabolism and inflammation in relation to radiographic parameters and pain of the knee: data from CHECK, a cohort of early-osteoarthritis subjects

OBJECTIVE

To investigate associations of biochemical markers of joint metabolism and inflammation with minimum joint space width (JSW) and osteophyte area (OP area) of knees showing no or doubtful radiographic osteoarthritis (OA) and to investigate whether these differed between painful and non-painful knees.

DESIGN

Serum (s-) and urinary (u-) levels of the cartilage markers uCTX-II, sCOMP, sPIIANP, and sCS846, bone markers uCTX-I, uNTX-I, sPINP, and sOC, synovial markers sPIIINP and sHA, and inflammation markers hsCRP and erythrocyte sedimentation rate (ESR) were assessed in subjects from CHECK (Cohort Hip and Cohort Knee) demonstrating Kellgren and Lawrence grade ≤1 OA on knee radiographs. Minimum JSW and OP area of these knees were quantified in detail using Knee Images Digital Analysis (KIDA).

RESULTS

uCTX-II levels showed negative associations with minimum JSW and positive associations with OP area. sCOMP and sHA levels showed positive associations with OP area, but not with minimum JSW. uCTX-I and uNTX-I levels showed negative associations with minimum JSW and OP area. Associations of biochemical marker levels with minimum JSW were similar between painful and non-painful knees, associations of uCTX-II, sCOMP, and sHA with OP area were only observed in painful knees.

CONCLUSIONS

In these subjects with no or doubtful radiographic knee OA, uCTX-II might not only reflect articular cartilage degradation but also endochondral ossification in osteophytes. Furthermore, sCOMP and sHA relate to osteophytes, maybe because synovitis drives osteophyte development. High bone turnover may aggravate articular cartilage loss. Metabolic activity in osteophytes and synovial tissue, but not in articular cartilage may be related to knee pain.

Personalised treatment using serum drug levels of adalimumab in patients with rheumatoid arthritis: an evaluation of costs and effects

OBJECTIVE

To evaluate the cost-effectiveness of personalised treatment for rheumatoid arthritis (RA) using clinical response and serum adalimumab levels.

METHODS

A personalised treatment algorithm defined, based on clinical (European League Against Rheumatism) response and drug levels at 6 months, whether adalimumab treatment should be continued in a specific dose or discontinued and/or switched to a next biological. Outcomes were simulated using a patient level Markov model, with 3 months cycles, based on a cohort of 272 adalimumab-treated patients with RA for 3 years and data of patients from the Utrecht Rheumatoid Arthritis Cohort. Costs, clinical effectiveness and quality adjusted life years (QALYs) were compared with outcomes as observed in usual care and incremental cost-effectiveness ratios were calculated. Analyses were performed probabilistically.

RESULTS

Clinical effectiveness was higher for the cohort simulated to receive personalised care compared with usual care; the average difference in QALYs was 3.84 (95 percentile range -8.39 to 16.20). Costs were saved on drugs: €2 314 354. Testing costs amounted to €10 872. Mean total savings were €2 561 648 (95 percentile range -3 252 529 to -1 898 087), resulting in an incremental cost-effectiveness ratio of €666 500 or €646 266 saved per QALY gained from a societal or healthcare perspective, respectively. In 72% of simulations personalised care saved costs and resulted in more QALYs, in 28% it was cost saving with lower QALYs. Scenario analyses showed cost saving along with QALYs gain or limited loss.

CONCLUSIONS

Tailoring biological treatment to individual patients with RA starting adalimumab using drug levels and short-term outcome is cost-effective. Results underscore the potential merit of personalised biological treatment in RA.

Inhibition of tissue factor pathway inhibitor by the aptamer BAX499 improves clotting of hemophilic blood and plasma

BACKGROUND

Tissue factor pathway inhibitor (TFPI) is the major inhibitor of tissue factor-initiated coagulation, making it an interesting and novel therapeutic target in hemophilia treatment. The aptamer BAX499 (formerly ARC19499) is designed to improve hemostasis by specifically inhibiting TFPI.

OBJECTIVES

The aim of the study was to examine the concentration-dependent augmentation of clotting by BAX499.

METHODS

Whole blood clot formation was quantified by rotational thromboelastometry and thromboelastography, and thrombin generation in platelet-poor plasma was assessed with the calibrated automated thrombogram, in samples from patients with congenital hemophilia A (N=55) and B (N=11), patients with acquired hemophilia A (N=1), and healthy controls (N=37).

RESULTS

BAX499 significantly improved clotting of samples from hemophilic patients in a concentration-dependent manner, resulting in clotting profiles in samples from patients with severe hemophilia that were similar to those of healthy controls.

CONCLUSION

BAX499 improved ex vivo clotting parameters in blood and plasma from patients with hemophilia A and B with different severity of disease, and also in a patient with acquired hemophilia. These results further support the contention that anti TFPI strategies may be an effective treatment for hemophilic patients.

Dacryo salivary fistula. Unusual case of salivary fistula draining into the inferior fornix of the eye

Salivary fistula after a traumatic injury in the buccal region is not common. It is most commonly encountered in injuries involving the pre auricular region or soft tissues along the course of the parotid duct. It is more frequent in the parotid because its anatomical location is superficial; traumatic salivary fistulae of the other two major salivary glands are rare. This report presents an unusual case of a salivary fistula that occurred following trauma to the infraorbital region and drained into the inferior fornix of the left eye. A review of cases reported in the literature is presented. This is the only case of such a presentation the authors have found after a thorough search of the relevant English language literature.

Molecular basis of Bernard-Soulier syndrome in 27 patients from India

BACKGROUND

Bernard-Soulier syndrome (BSS) is an extremely rare (1:1 million) bleeding disorder of platelet adhesion, caused by defects in the glycoprotein (GP)Ib/IX/V complex.

PATIENTS AND METHODS

The diagnosis in 27 patients was based on low platelet count, presence of giant platelets and aggregometry studies. Flow cytometry to assess the surface GPIb/IX/V complex showed reduced (7.7-57%) expression. gDNA was screened for mutations in the GPIBA, GPIBB, GP9 genes using PCR-conformation sensitive gel electrophoresis (CSGE).

RESULTS

Thirteen different disease-causing mutations, including missense (54%), frameshifts (38%) and nonsense (8%) mutations, were identified in 27 patients. Eleven of them were novel including five novel frameshifts (GPIbα: p.Gln97_98fsX113, p.Pro402_403fsX52; GPIbβ: p.Arg17fsX14; GPIX: p.Gly24fsX43, p. Pro130fs, a nonsense mutation (GPIX, p.94, Gln>X) and five novel missense mutations (GPIbα: p.492, Tyr>His; GPIbβ: p.65, Pro>Arg, p.129, Gln>His, p.132, Leu>Pro; GPIX: p.55, Phe>Cys). Interestingly, four common mutations, Cys8Arg (n = 6) and Phe55Ser (n = 2), Phe55Cys (n = 2) in GPIX and a novel 22-bp deletion in the GPIBB gene predicting p.Arg17fsX 14 (n = 10) were seen in 20 patients.

CONCLUSION

The molecular data presented here is the largest series of BSS patients to be reported so far, adding significantly to the mutation database of this condition and also useful for its genetic diagnosis in India.

Underlying prothrombotic states in pregnancy associated cerebral venous thrombosis

BACKGROUND

The exact pathogenesis of pregnancy associated cerebral venous thrombois is still unsettled. Aims : To identify possible inherited and acquired prothrombotic risk factors and also identify the factors associated with mortality in pregnancy associated CVT.

SETTINGS AND DESIGN

Prospective cohort study to identify prothrombotic risk factors and case control study of influence of local traditional practice of puerperal water restriction on postpartum CVT.

MATERIALS AND METHODS

Consecutive patients with pregnancy associated CVT seen over a period of three years. Thrombotic workup included genetic markers, protein assays, and other factors.

STATISTICAL ANALYSIS

Univariate and chi-square analysis.

RESULTS

Of the 41 patients studied during the study period, 71% of patient had a single and 34% had multiple prothrombotic risk factors. Methylene tetrahydro-folate reductase (MTHFR) heterozygosity (19.5%) and factor V Leiden heterozygous (7.3%) were the commonest genetic markers. Hyperhomocysteinemia (34%) and elevated factor VIII levels (14.6%) were the other important risk factors. In this cohort the mortality was 17%. Mortality increased by odds of 1.3 for every additional prothrombotic marker. The factors associated with increased mortality included: status epileptics (P = 0.05, OR 13.2, 95% CI 1.002 - 173), deep venous system involvement (P = 0.016, OR 9.64, 95% CI 1.53 - 60.6), presence of midline shift (P = 0.012, OR 24.7, 95% CI 2.05 - 29.8) and diffuse cerebral edema (P = 0.006, OR 14.5, 95% CI 2.18- 96.4). The traditional practice of decrease intake of water during puerperium was significant in woman with pregnancy associated CVT when compared to control subjects (P < 0.02).

CONCLUSION

In patients with pregnancy associated CVT, prothrombotic markers can be multiple and are associated with increased odds of mortality. Deep venous system involvement, presence of midline shift and diffuse cerebral edema increased mortality. Peuperial water restriction may be a modifiable risk factor.

Polymorphism in factor VII gene modifies phenotype of severe haemophilia

The basis for 10-15% of patients with severe haemophilia having clinically mild disease is not fully understood. We hypothesized that polymorphisms in various coagulant factors may affect frequency of bleeding while functionally significant polymorphisms in inflammatory and immunoregulatory genes may also contribute to variations in the extent of joint damage. These variables were studied in patients with severe haemophilia, who were categorized as 'mild' (<5 bleeds in the preceding year, <10 World Federation of Haemophilia clinical and <10 Pettersson scores, n = 14) or 'severe' (all others, n = 100). A total of 53 parameters were studied in each individual for their association with the clinical severity. Age, F8:c activity and the incidence of thrombotic markers were comparable between the groups while the median number of bleeds, number of affected joints, clinical, radiological and functional joint scores (P < or = 0.001) and life-time clotting factor use (P < or = 0.007) were different. Patients with severe molecular defects had a 4.1-fold increased risk for a severe phenotype (95% CI: 1.18-14.42, P = 0.026) compared with other mutations. Of the polymorphisms studied, the FVII353Q (RR = 3.5, 95% CI: 1.04-12.05, P = 0.044) allele was associated with a severe phenotype. This data shows that apart from the F8/F9 genotype, functional polymorphisms in FVII gene affect the phenotype of patients with severe haemophilia.

Fracture neck of femur in haemophilia A ? experience from a cohort of 11 patients from a tertiary centre in India

We describe here the management of eleven patients with fracture neck of femur. Excepting one patient all had severe haemophilia A. Nine patients were less than 50 years of age. Eight out of eleven patients had fracture after trivial trauma. Nine patients had closed reduction and one patient open reduction. The patient with non union had a Valgus osteotomy. All fractures united. The average time to union was 11 weeks (range:8-16). We followed either a low dose intermittent or a low dose continuous infusion factor support protocol for the management of these patients. The median dose of factor support was 252 u/kg (range: 136-580). The average duration of factor support was 9 days (range: 7-10). Two patients had aggravation of pre existing knee stiffness following post operative immobilisation. No other major complication was observed in this cohort of patients. To conclude, management of fracture neck of femur in patients with haemophilia is no different from general population if an adequate haemostasis is achieved.

Achieving and maintaining quality in the laboratory

In order to ensure the delivery of a service of the highest possible quality, it is an essential requirement that laboratories undertake strict internal quality control (QC) measures as well as participate in external quality assessment (EQA) schemes. For any given test, a critical part of the internal QC process involves the establishment of reference intervals using samples taken from normal individuals, and then calculating limits representing the 95% range. This forms the basis for assessment of abnormal test results, which will in turn impact on laboratory performance in proficiency testing exercises in EQA programmes. Whereas for plasma-based assay systems, variability in performance in EQA exercises is usually determined by measurement of a coefficient of variation (CV), results of genetic testing is usually measured in absolute terms. Despite this, results of genetic EQA programmes confirm that errors in testing do occur, as much because of inadvertent sample switching and transcription errors as to analytical mistakes. EQA programmes involving identification of mutations by DNA sequencing, such as haemophilia, is made difficult by the high information content of sequence data. Nevertheless, results show that errors are usually made in the naming of the mutations, indicating that this is an evolving and poorly standardized area. Developing countries face particular challenges in the encouragement of laboratories to participate in local EQA programmes, as well as in relation to the logistical issues of sample provision, distribution and result collation in an effective and affordable manner.

Identification of factor VIII gene mutations in 101 patients with haemophilia A: mutation analysis by inversion screening and multiplex PCR and CSGE and molecular modelling of 10 novel missense substitutions

Haemophilia A (HA) is an X-linked bleeding disorder caused by diverse mutations in the human coagulation factor VIII (FVIII) gene. We have analysed DNA from 109 unrelated Indian patients with HA for their FVIII gene defects. Among these patients 89 (82%) had severe (FVIII:C <1%) HA, 11 (10%) had moderate (FVIII:C 1-5%) HA and nine (8%) had mild (FVIII:C 5-30%) HA. These patients were first screened for the common intron 22 and intron 1 inversions. Inversion negative samples were screened for point mutations by a multiplex PCR and conformation sensitive gel electrophoresis strategy. Mutations were identified in 101 of the 109 patients. These included two (2%) intron 1 and 51 (51%) intron 22 inversions, four (4%) gross deletions and 44 (43%) point mutations. Twenty-nine novel causative mutations, including 11 missense, seven frameshift, five nonsense mutations, three splice site defects and three gross deletions were detected. Ten of the novel missense mutations were studied by molecular modelling. Two different (Thr2253Pro and Pro1392fs) mutations were seen in four unrelated families and FVIII gene haplotyping suggested a common founder effect. Seven of these 109 patients had inhibitors. Among them, four had intron 22 inversions, one had a novel gross deletion (delexon 2-9) and one a nonsense mutation (Trp1535Stop). In one of these patients, no mutation could be identified in the FVIII gene. A Thr2253Pro novel mutation and an intron 22 inversion were identified in two female haemophiliacs. The data from this study suggests that the spectrum of gene defects in Indian patients with HA is as heterogeneous as reported in other populations.

Diversity of Glanzmann thrombasthenia in southern India: 10 novel mutations identified among 15 unrelated patients

BACKGROUND

Glanzmann thrombasthenia (GT) is a congenital bleeding disorder caused by either a lack or dysfunction of the platelet integrin alphaIIbbeta3.

OBJECTIVES

To determine the molecular basis of GT in patients from southern India.

PATIENTS

Fifteen unrelated patients whose diagnosis was consistent with GT were evaluated.

RESULTS

Platelet surface expression of alphaIIbbeta3 was < 10%, 10%-50%, and > 50% of controls in five, nine, and one patient(s), respectively. Immunoblotting of the platelet lysates showed no alphaIIb in 14 patients, and no beta3 in 10 patients, although severely reduced in four patients. Platelet fibrinogen was undetectable in 13 patients, and severely reduced in one patient. One patient showed normal surface alphaIIbbeta3 expression, and normal alphaIIb, beta3 and fibrinogen levels in the lysate. Ten novel candidate disease-causing mutations were identified in 11 patients. The missense mutations included Gly128Ser, Ser287Leu, Gly357Ser, Arg520Trp, Leu799Arg in alphaIIb, and Cys575Gly in beta3. We have already shown that Gly128Ser, Ser287Leu, and Gly357Ser mutations variably affect alphaIIbbeta3 surface expression. The Cys575Gly mutation may disrupt the disulphide link with Cys586 to cause the GT phenotype. The molecular pathology of the other missense mutations is not clear. Two nonsense mutations, Trp-16Stop and Glu715Stop in alphaIIb, and a 7-bp deletion (330-336TCCCCAG) in beta3 are predicted to result in truncated proteins. An IVS15(-1)G --> A mutation in alphaIIb induced a cryptic splice site as confirmed by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Thirteen polymorphisms were also identified (five in alphaIIb and eight in beta3), among which five were novel.

CONCLUSIONS

While identifying a significant number of novel mutations causing GT, this study confirms the genetic heterogeneity of the disorder in southern India.

Laboratory issues in bleeding disorders

The clinical history of the patient and of his/her relatives is the most important tool for making correct diagnosis of inherited or acquired bleeding disorders. Several attempts have been made by clinicians to evaluate the sensitivity and specificity of bleeding symptoms. Specific and detailed questionnaires have been designed to quantify the bleeding tendency of patients with von Willebrand's disease (VWD) and a bleeding score has been calculated. VWD is considered the most frequent inherited bleeding disorder according to population studies: however, due to the complexity of its diagnosis, the number of patients with correct diagnosis of VWD in many developing countries is relatively low and most cases remain still under- or misdiagnosed. Once bleeding history is carefully evaluated by means of a bleeding score, the laboratory workout should be organized to find out the specific defect of haemostasis responsible for bleeding. Since factors involved in haemostasis are many, the correct approach must include first level screening tests with the aim to identify the abnormal phase of haemostasis involved: then, second level tests should be focused on the specific factors within the abnormal step of haemostasis. Among many other acquired bleeding disorders related to clinical conditions or to the use of drugs, the acquired inhibitors of haemostasis are rare but should be immediately characterized by appropriate laboratory tests because they can be often life-threatening for the patients.

Molecular genetics of hereditary prothrombin deficiency in Indian patients: identification of a novel Ala362 --> Thr (Prothrombin Vellore 1) mutation

Prothrombin deficiency is a rare (1:200 000) autosomal recessive disorder caused by diverse mutations in prothrombin gene. We have studied the molecular basis of this disorder in four unrelated Indian patients. The diagnosis was based on prolonged prothrombin (PT) and activated partial thromboplastin times and low factor II coagulant activity (FII: C) measured using a PT based assay. FII: C levels ranged between 4.7% and 17.5%. Mutations were identified in all the four patients. Five different causative mutations including four (80%) missense and an in-frame deletion (20%) were identified. One of them was a novel, Ala362 --> Thr amino acid change affecting 'B' chain of -thrombin. This mutation was present in a compound heterozygous state with a previously reported Arg-1 --> Gln missense change affecting pro-peptide cleavage site. Ala362 --> Thr occurred at a codon, evolutionarily conserved in all the 24 different prothrombins or its related serine proteases studied. Molecular modeling of this mutation was found to cause a conformational change around the region involving a catalytic triad residue His363 and a cysteine residue at codon 364. The FII: C level in this patient was 17.5%. Three other previously reported mutations were also detected in the homozygous state: Arg271 --> Cys in Kringle-2 region, a Glu309 --> Lys in "A" chain of -thrombin and an in-frame deletion of 3 bp (AAG) leading to Del Lys301/302 in "A" chain of -thrombin. This is the first report of the molecular basis of prothrombin deficiency in Indian patients and we suggest the eponym 'Prothrombin Vellore 1' for Ala362 --> Thr mutation.

Six novel mutations including triple heterozygosity for Phe31Ser, 514delT and 516T-->G factor X gene mutations are responsible for congenital factor X deficiency in patients of Nepali and Indian origin

Factor X (FX) deficiency is a rare (1 : 100000) autosomal recessive disorder caused by heterogeneous mutations in FX gene. We have studied the molecular basis this disease in six Indian and one Nepali patients. Diagnosis was confirmed by measuring the FX coagulant activity (FX: C) using a PT based assay. Six of them had a FX: C of < 1% and one patient had 24% coagulant activity. Mutations were identified in all the seven patients. These included eight (88.8%) missense and one frame-shift (11.2%) mutations of which six were novel. Three of the novel mutations, a Phe31Ser affecting 'Gla' domain and 514delT and 516T-->G mutations affecting Cys132 in 'connecting region' were identified in a triple compound heterozygous state in a Nepali patient presenting with a severe phenotype. Two other novel mutations, Gly133Arg, may affect the disulphide bridge between Cys132-Cys302 in the connecting region while Gly223Arg may perturb the catalytic triad (His236, Asp282 and Ser379). The other novel mutation, Ser354Arg, involves the replacement of a small-buried residue by a large basic aminoacid and is likely to have steric or electrostatic effects in the pocket involving Lys351-Arg347-Lys414 that contributes to the core epitope of FXa for binding to FVa. Three previously reported mutations, Thr318Met; Gly323Ser; Gly366Ser were also identified. This is the first report of the molecular basis of FX deficiency in patients from the Indian subcontinent.

Evaluation of primary haemostasis in people with neurofibromatosis type 1

Assessment of haemostasis in people with neurofibromatosis type 1 (NF-1) is essentially lacking, despite case reports of an association with von Willebrand disorder (VWD) and reported excessive bleeding post-surgery. We assessed routine blood haematology, routine coagulation parameters [prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen], coagulation factors II, V, VII, VIII, IX, X, XI and XII, von Willebrand (VWF) factor antigen and activity, and platelet function [using the platelet function analyser (PFA-100)] in a group of individuals with NF-1 (n = 30). Their perceived haemorrhagic bleeding risk was also graded by means of a structured clinical assessment and physical examination. Routine blood assessments including platelet counts were generally normal, as were the routine coagulation tests PT, TT and fibrinogen, and most coagulation factors. Elevated APTTs were detected in 11 individuals, reduced factor XII levels in three, reduced VWF levels in four, and elevated PFA closure times (CTs) in 13. Laboratory results correlated with each other in some but not all cases. For example, elevated APTTs were identified in two of three individuals with a reduced factor XII level and prolonged CTs were identified in three individuals who also showed reduced aggregation responses in classical platelet function studies. Moreover, all individuals with VWF results below the normal reference range showed elevated CTs with both PFA test cartridges, and those with VWF results identified as borderline normal (i.e. 50-65%) also showed elevated CTs with both PFA test cartridges in three of five cases. The relationship between VWF and CTs was also identified by linear regression analysis (P-values of <0.05, for all comparisons). However, as clinically perceived bleeding risk did not appear to be correlated with laboratory test results in most cases, blanket screening of NF-1 individuals for evaluation of laboratory haemostasis may not be warranted.

Normal hematological indices, blood chemistry and histology and ultrastructure of pancreatic islets in the wild Indian bonnet monkeys (Macaca radiata radiata)

The present study is aimed at determining some haematological and biochemical parameters in the wild Indian bonnet monkeys as also the microscopic and ultrastructural characteristics of their pancreatic islets. Adult wild Indian bonnet monkeys (Macaca radiata radiata) of both sexes weighing between 2.5 and 4 kg were used in these experiments. Their platelet, reticulocyte and total leukocyte counts and the blood concentrations of hemoglobin and plasma proteins and the serum concentrations of aspartate amino transferase, alanine amino transferase and calcium are similar to the values reported for M. mulatta. Plasma glucose is lower when compared with reported values of M. mulatta and M. fascicularis. Insulin levels are comparable with those of M. mulatta and M. nigra. Histology of islets is similar to that of humans. Ovoid cell collections of islet cells are scattered throughout the pancreas. Ultrastructure of A, B and D cells is similar to humans. These findings suggest that this relatively underutilized macaques may be a suitable model for biomedical research.

Distribution of ABO and Rh-D blood groups among blood donors in a tertiary care centre in South India

The distribution of ABO and Rh-D blood groups was studied among 150,536 blood donors screened at the Dr John Scudder Memorial Blood Bank, Christian Medical College Hospital, Vellore, over a period of 11 years (April 1988 to March 1999). The most common blood group was found to be group O [58,330 (38.75%)], followed by group B [49,202 (32.69%)], and group A [28,372 (18.85%)]. The least common blood group was AB group [7,930 (5.27%)]. A2 or A2B groups were found in 3.01% and 1.43% of donors, respectively. The prevalence of Rh-D negative group was found in 8,225 (5.47%) donors. Bombay group (H negative non-secretor, genotype hh phenotype Oh) was found in six donors (0.004%). Although the incidence of Rh-D negative group was identical to previously published data from North India, the most common blood group was O group in our study as opposed to B group.

Haemostasis with cryoprecipitate in patients undergoing surgery for severe von Willebrand disease

BACKGROUND

There are limited data on the management of haemostasis in patients with severe von Willebrand disease undergoing major surgery. Data on the use of cryoprecipitate in this setting are even more limited. In many developing countries cryoprecipitate is often the only available source of factor replacement. The minimum factor levels required for maintaining haemostasis after surgery have never been carefully evaluated.

METHODS

Data from 3 patients with severe von Willebrand disease who underwent 4 major surgical procedures at our institution, using lower than standard recommended doses of cryoprecipitate were analysed for adequacy of factor replacement and complications.

RESULTS

The average preoperative cryoprecipitate infusion was 22.5 i.u. of factor VIII/kg (range: 15-25). The bleeding time done by the modified Ivy method, 30 minutes after infusion, was normal in all these patients. The average cryoprecipitate support for days 1-3 was 16.5 i.u. of factor VIII/kg/day (range: 12.5-25) and for days 4-10 was 12.4 i.u. of factor VIII/kg/day (range: 8.3-16). The mean duration of factor replacement was 12 days (range: 7-17). Two patients had delayed bleeding, one on day 3 attributed to the inadvertent use of a non-steroidal anti-inflammatory drug and the second on day 10 which was probably secondary to septicaemia. Bleeding resolved in both these patients as soon as the precipitating factors were relieved.

CONCLUSION

The total amount of factor replaced in our patients is approximately half of what would have been used if the usual recommendations were followed. The data suggests that lower doses of cryoprecipitate could be adequate for major surgery and wound healing in severe von Willebrand disease. This will lead to lowering of costs and reducing the risk of transfusion-associated virus infection.

Evaluation of uroprotective efficacy of amifostine against cyclophosphamide induced hemorrhagic cystitis

The role of amifostine in the prevention of cyclophosphamide-induced hemorrhagic cystitis (HC) was evaluated in the rat model. Urinary bladders from control rats that received no drugs (group I) were compared with those from rats receiving cyclophosphamide alone at a dose of 150 mg/kg (group II), and two other groups receiving amifostine at 100 mg/kg (group III) and 200 mg/kg (group IV), 15 min prior to cyclophosphamide. Bladders were assessed macroscopically and histologically at 24 h and after 7 days. All the animals that received cyclophosphamide alone developed severe HC. On the basis of the scores of macroscopic and histologic changes, animals that received amifostine showed excellent uroprotection. Only 2/6 rats in group III and 1/6 rats in group IV developed mild HC at 24 h. None of the rats in either of these groups showed any evidence of HC at 7 days. It is concluded that amifostine protects the urothelium against cyclophosphamide-induced HC.

Low-dose intermittent factor replacement for post-operative haemostasis in haemophilia

Recommendations for factor replacement therapy for postoperative haemostasis in haemophilia are often empirical and based on the physiological understanding of haemostatic requirements. This report describes the haemostatic management of patients with severe haemophilia undergoing major surgery using lower than usually recommended levels of factor replacement therapy. Eighteen adults (11 with FVIII and seven with FIX deficiency) with an average weight of 52 kg (range: 27-69) underwent 20 major surgical procedures. Factor concentrates were administered by intermittent bolus infusions. The dose of FVIII infused before surgery was 76 mu kg-1 (range: 51-113) and that of FIX was 77 mu kg-1 (range: 50-104). The preoperative levels achieved were 107% (range: 80-180) and 73% (range: 60-90), respectively. Between days 1 and 3 after surgery, an average of 29 mu kg-1 day-1 (range: 20-46) of FVIII and 23 mu kg-1 day-1 (range: 12-42) of FIX was used resulting in mean trough levels of 36% (range: 12-62) and 34% (range: 11-52), respectively. After day 4, an average of 19 mu kg-1 day-1 (range: 15-25) of FVIII and 18 mu kg-1 day-1 (range: 10-37) of FIX was administered until wound healing. The average duration of factor replacement was 11 days (range: 8-16). The mean dose of factor concentrate per patient was 260 mu kg-1 (range: 179-338) of FVIII and 300 mu kg-1 (range: 183-524) of FIX. The total amount of factor used per patient ranged from 12,380 to 19,980 units of FVIII and 8000 to 23,600 units of FIX. Only one patient had post-operative bleeding which was due to a surgical cause. It is concluded that it may be possible to use much lower than recommended levels of factor replacement therapy for postoperative haemostasis in severe haemophilia.

Analysis of FKBP51/FKBP52 chimeras and mutants for Hsp90 binding and association with progesterone receptor complexes

FKBP51, FKBP52, and Cyp40 bind competitively to Hsp90 through their respective tetratricopeptide repeat (TPR) domains, and any one of the three immunophilins can be isolated in mature steroid receptor complexes. During cell-free assembly reactions, FKBP51 associates preferentially with progesterone and glucocorticoid receptors, but less preference is observed in FKBP51 association with estrogen receptor. A number of mutant FKBP forms were generated to map sequences responsible for FKBP51's preferred association with progesterone receptor. A double-point mutation in the peptidyl prolyl isomerase domain of FKBP51 that reduces enzymatic activity by greater than 90% had no observed effect on FKBP51 interactions with progesterone receptor or Hsp90. Coprecipitation of FKBP51 and FKBP52 truncation mutants with Hsp90 indicated that sequences both upstream and downstream of the TPR domain are necessary for Hsp90 binding. FKBP chimeric constructs were also generated and tested for Hsp90 binding and receptor association. The TPR domain of FKBP51 required appropriate downstream sequences for Hsp90 binding, but FKBP52's TPR domain did not. The C-terminal region of FKBP51 that functionally interacts with the TPR domain to permit Hsp90 binding also conferred preferential association with PR. In conclusion, despite the overall similarity of FKBP51 and FKBP52, these two immunophilins associate differentially with steroid receptors, and the difference relates to both the Hsp90-binding TPR domain and to poorly conserved C-terminal sequences.

Molecular cloning of human FKBP51 and comparisons of immunophilin interactions with Hsp90 and progesterone receptor

A cDNA for human FKBP51 has been cloned and sequenced, and protein products have been expressed in both in vitro and bacterial systems. The deduced amino acid sequence for human FKBP51 is 90% identical to sequences of recently described murine proteins and is 55% identical to the sequence of human FKBP52. Human FKBP51 mRNA is expressed in a wide range of tissues, and the protein has peptidylprolyl isomerase activity that is inhibited by FK506 but not cyclosporine. FKBP51 is the same as a previously described progesterone receptor-associated immunophilin that, similar to FKBP52 and cyclophilin 40, is an Hsp90-binding protein and appears in functionally mature steroid receptor complexes along with Hsp90 and p23. Each of the three receptor-associated immunophilins displays interactions with progesterone receptor that are more dynamic than Hsp90-receptor interactions. Whereas FKBP52 and FKBP51 compete about equally well for binding to Hsp90 in a purified system, FKBP51 accumulates preferentially in progesterone receptor complexes assembled in a cell-free system. This observation provides a precedent for differential interactions between Hsp90-associated immunophilins and target proteins such as steroid receptors.

A pathway of multi-chaperone interactions common to diverse regulatory proteins: estrogen receptor, Fes tyrosine kinase, heat shock transcription factor Hsf1, and the aryl hydrocarbon receptor

A variety of regulatory proteins, including different classes of transcription factors and protein kinases, have been identified in complexes with Hsp90. On careful examination of unactivated progesterone receptor complexes, eight different protein participants have been identified, and each can be considered a component of the cytoplasmic molecular chaperone machinery. These proteins are Hsp90, Hsp70, Hip, p60, p23, FKBP51, FKBP52 and Cyp40. Studies in a cell-free assembly system have helped to define a highly ordered, dynamic pathway for assembly of progesterone receptor complexes. In the present study, target proteins other than progesterone receptor were used in this cell-free system to assemble complexes in vitro and to compare the composition of resulting complexes. Targets used were human estrogen receptor, human Fes protein-tyrosine kinase, human heat shock transcription factor Hsf1, and human aryl hydrocarbon receptor. The striking similarity of resulting target complexes with previously characterized progesterone receptor complexes suggest that each of these targets undergoes a common assembly pathway involving multiple chaperone components in addition to Hsp90.